Counterweights for Hadley, using Coins for weight

Do you have a jar of coins collecting dust on a shelf? Put them to good use! 

This counterweight for Hadley uses a stack of US cents, euro cents or other coins as a cheap and readily available mass. 

For a general-purpose version with closed top and bottom for bulk media like BBs see Counterweight for Hadley, using BBs or lead shot for weight

It makes it easy to balance the telescope when changing accessories like eyepieces, camera or phone, without having to move the middle mount. 

The counterweight clips onto the tube; there are versions for both imperial (½ inch) and metric (12 mm) tubes.

Sizes 

Select the holder depending on what coins you have around in US, euro or other denominations. Or use the large bulk / general purpose holder for BBs or anything else. 

Small: about 2 oz / 60 gram

• 19.5 mm inside diameter

• 20x US cents

• 17x 2-euro cents

Small Extended: about 4 oz / 120 gram

• 19.5 mm inside diameter

• 40x US cents

• 34x 2-euro cents

Medium: about 3 oz / 90 gram

• 22.0 mm inside diameter

• 17x US 5-cents

• 20x 5-euro cents

Large: about 4 oz / 120 gram

• 24.5 mm inside diameter

• 20x US quarters

• 16x 20-euro cents

Printing instructions

• Print the Holder in PLA, 0.2 mm layer height, with scarf joints and 3 perimeters.

• Print the Cap in PLA, 0.15 mm layer height, with scarf joints.

• No supports required.

• 25 to 45 minutes print time on a Mk4, depending on holder size.

Assembly instructions

• Stack coins in the holder

• Screw on the cap 

• The threads might be a bit stiff initially, add a bit of candle wax to lubricate if needed.

Use instructions

• Clip the counterweight onto one of the tubes.

• Orient it to keep it out of the optical path.

• Slide it to fine adjust the balance. 

Creator's note 

• The design was tested with US coins and ½ inch tube; let me know how it works for metric / euro cents.

• This design was in part inspired by Hadley telescope camera counterweight by Xypris

• Hadley is a fun thing to design for, check out my other designs in Redlow's Hadley Add-Ons Collection

• Designed to fit various coins
• Threaded cap, no screws required